Expanding auger



June 39, E923. 3,459,36fi

A. GOSPER EXPANDING AUGER Filed Aug. 31 1921 Patented June 19, 1923.

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AMOS sosrna, or BaNKsIe, NEAR. SYDNEY, NEW SOUTH vvALns, AUSTRALIA, AS-

SIGNOR TO HENRY PETRIE FLETGHEB, OF SYDNEY, NEW SOUTH WALES, AUS-Til-ALIA.

' EXPANDING Ans-En.

Application filed August 31. 1921. serial 310. 497,252.

To aZZ who/2t it may] concern:

Be it known that 1, Amos Gosrnn, a subject of the King of Great Britain,residing at Banksia, near Sydney, in the State of New South Wales,Commonwealth of Australia, have invented new and useful Improvements inExpanding Angers of which thefollou ing is aspecification This inventionrelates to an improved selfcontained tool for boring-an undercut orreverse taper hole in woodor the like in one operation. Moreparticularly it has ref- .erence to a tool having a cutting elementadapted to incline outwardly as it enters the material. being bored,with provision for counter-sinking around the smallest diameter of thehole formed.

A feature of the invention resides in provision for the work being fedto the tool and, further, in causing the cutting element to bede-aligned from the vertical to an inclined plane in synchronism withand under the pressure exerted by the progressive feeding travel of thework, and, still further, in returning the operative elements of thetool to their initial positions as and when the work is withdrawn afterboring and countersinking hav been completed.

With these and other objects in view,

the invention consists of the features of construction, combination andarrangement hereinafter fully described reference being had to theaccompanyingdrawings where- Figure 1 is a part sectional elevation ofthe invention.

Figure 2 is a cross-sectional plan taken on line A.A Figure 1.

Fig. 3 is a cross-sectional View on line BB of Fig. 1.

A tool according to the invention comprises a spindle 2 having a taperedupper end 3 terminating in a lug 4- by which attachment to a drillingmachine or the like is effected.

The spindle is provided with a slot-way 5 wherein is mounted a pivot pin6 to support the boss 7 of a cutter control member or tongue 8accommodated in the slot-way of said spindle. The tongue 8 normallyprojccts beyond the edge of the spindle 2 under the influence of acoiled spring 9, the outer end of which bears in a recess 10 formed inthe upper end of the tongue. The inner end of the spring 9 bears in arecess 11 formed in the spindle and in comn'iunication' withthe slotwaythereof. Threaded into or otherwise secured to the lower end of thetongue 8 is the upper end of a cutting element or bit 12. V

Formed in the lower nd-o1. the tongue 8 is an inclined hole or slotaccommodating a removable counter-sink 13; The countersink may betapered and retained by a driving iit or it may b otherwise securedThreaded upon the spindle 2, below the tapered portion 3 thereof, isanut 141 adapted to retain an upper ball bearing 15; Bearing against theupper ball bearing 15 is an upper inverted cup 16 into which projectsthe upper end of a compression spring 17 encircling the spindle2. Thelower end of the spring 17 is accommodated in a lower cup 18 restingupon an externally threaded nut 19 adapted to retain a lower ballbearing 20 within a holder 21. The bearing 20 encircles the lower end ofthe spindle 2 and normally rests upon limit stops 22 carried by the saidspindle.

The holder 21 is constructed with a central hole 23 and is provided withholding pins or spikes 24 adapted to enter the material to be bored.

In use, the spindle 2 is secured by the lug 4 to a. drilling machine orthe like and rotated thereby, the material to be bored being disposedbelow the holder 21 and fed towards the cutting element 12 by any knownor suitable means. The pins or spikes 24 enter the material and preventit from rotating under the influence of the rotating cutting element 12.As the material or work advances towards the cutting element 12 theholder 21 and ball bearing 20 and nut 19 move along the spindle 2, thetongue 8 being forced inwardly against the pressure of the spring 9 bycontact with the encircling hearing 20.

It will be obvious that as the upper end of the tongue 8 moves into theslotway indicated at 5 the cutting element 12 carried by the lower endof the tongue 8 moves outwardly and is inclined to the axis of thespindle 2. A hole is thus cut by the rotating cutting element 12, whichis larger at the inner or lower end than at the point of entry. Upon thework being fed a pre-determined distance in relation to the cuttingelement 12 the counter-sink 13 engages the material and by enlarging thenarrow end of the hole out forms a counter-sunk recesssimultaneouslywith the completion of the hole by the cutting element 12.

The spring 17 is compressed when the work is fed to the cutting element12 and the holder 21 and its appurtenances are ol viously returned totheir initial position under its influence as the work is withdrawn. Thespring 9 then'itorces the upper end of the tongue 8 outwardly, therebyreturning the cutting element 12 into vertical alignment with thesoindle 2. Should it be de sired to form reverse tapered holes without acounter-sunk narrow end the counter-sink 15') is removed and theapparatus functions as alread described. I

hat I do claim is LA tool for boring reverse taper holes comprising aspindle, a'pivoted cutter control member carried by the spindle, acutting element carried by the member, awork holder slidably mounted inrelation tov the spindle, a bearing in the holder including a memberthrough which the spindle and control member extend and arranged foractuating the control member and hence the cutter, a second bearing forthe spindle, and a spring between the bearings for returning I theholder to initial position upon completion of boring, and for alsoreturning the control member and the cutter to initial po-- the spindleand bearing againstthe tongue,

at work holder carrying the bearing, a plurality of pins carried by theholder, and a, the spindle and coiled spring encircling bearing upon theholder.

In testimony whereof I aflix my signature in presence of a witness. 1 I

AMOS GOSPER, lVitness:

7. J. CREAGH.

